The extracellular matrix of connective tissue consists primarily of collagens, glycoproteins and proteoglycans. The collagenous components provide the tensile strength and a structural framework for the glycoproteins and proteoglycans. The non-collagenous components are often tissue specific and provide the functional properties characteristic of that particular tissue. The corneal stroma contains extracellular matrix components that interact, in an unknown way, to produce the optical transparency unique to this connective tissue. The corneal keratan sulfate proteoglycan is crucial to transparency. It appears during the acquisition of transparency and its loss or alteration produces opacities. We have tentatively identified four stromal glycoproteins and expect them to be likewise involved in matrix transparency. The long-term goals of this project are to define the interaction of the stromal matrix components that produce corneal transparency and to identify the genetic elements that regulate their production. The first aim is to use chromatographic procedures to isolate the non-collagenous components of the stromal matrix and then use immunological and biochemical procedures to partially characterize them. These studies will establish the general structure of these components and their tissue distribution, and will provide a means to initiate cDNA cloning studies. The second aim is to use recombinant DNA technology to isolate cDNA clones to these matrix components. The amino acid sequence deduced from the clones will determine its definitive structure and establish its relationship to other matrix components. The third aim is to use affinity chromatography to identify the interacting matrix components and their structural domains that account for the interaction. This information will define the molecular arrangement of the components within the matrix. The fourth aim is to initiate studies using recombinant DNA technology to establish the gene structure of these matrix components and identify the genetic elements that regulate their production. These regulatory elements will play an important role in the process involved in corneal development, wound healing and disease.